Tubing machine



Patented Sept. 6, 1932 UNITED STATES CHARLES EDGAR MAYNARD, OF NORTHAMPTON, V

FISK RUBBER COMPANY, OF CHICOPEE FALLS, MASSACHUSETTS, A CORPORATION;

OF MASSACHUSETTS 'P'ATE'NTQOFFICES MASSACHUSETTS, ASSIGFI'OR TO THE TUBING 11 mm v Application filed January 30, 1930'. Serial No. 424,322.

My invention relates to an improvement,

eration.

In the accompanying drawingwhich illustrates one-embodiment of my invention,

Fig. 1 is a longitudinal sectional view of the delivery end of a usual form of tubing. machine with my improvement embodied therein;

Fig. 2 is a section taken substantially on line 22 of Fig. 1; and

Fig. 3 is a section similar to Fig. 1, but

showing the invention applied to the extrusion of a solid bar of material.

In the drawing, 10 indicates the conventional feed screw operating in the barrel 11 of the machine, 13 indicating the conventional cavities for the circulation of cooling water. A spider 14 is held in the barrel 11 by abridge binder 15 screwed into the barrel. A die holder 16 is held against a shoulder 17 of the bridge binder 15 by a binder nut 18. A die 20 is maintained in position in the die holder 16 by the force of the stock pushing through the head in the direction of arrow 21.

The spider 14 supports a stem 22 upon which is fixed a compression member, which, I make in the form of a shell 23 and which is adapted to re-compress the stock after it has been forced through the spider 14. A core 24, which regulates the bore of the tube (the tube being shown in phantom at 25) when associated with the die 20, is carried by the stem 22, being adjusted by a stem nut 26. Screws 19 in the binder 15 are adapted to center the die 20 with respect to the core 24.

I have found that if the stock is cooled as it passes the compression shell 23 and core 24 a better stock condition is secured and the speed of extrusion may be increased to an extent substantially limited only by the ability of the screw 10 to advance a given stock.

Furthermore,I find that the diameterof the tube after it issues from the die may be varied by merely varying the degree of the cooling action of the shell and core, as for example, by increasing the flow of cooling fluid through the shell ashereinafter' explained.

In the illustration shown I accomplish the interior cooling of the tube by coring the compression shell ,23 a s'at 277cc provide an in ner cooling cavity. Thiscavity is fed by a duct 32 passing-through the barrel 11 and connecting with a passage or conduit '28 leading from the periphery of the spider through one of the spider spokes 29. A tube 30 fitted into theintake passage brings the incoming fluid to the extreme end of the cavity 27 to insure the cooling circulation throughout the Whole cavity. The cooling fluid, which may be water, escapes from the cavity through a passage 31 formed in another of the spider spokes 32 and connecting at the outer periphery of the spider with a duct 33 passing to the outside of the barrel.

In order to prevent adhesion of the inner walls of the extruded stock in case these walls should touch, it is customary to introduce soapstone or some similar material into the tube. This is done without interfering with the cooling arrangement by another passage 34 formed in another of the spider spokes and communicating with a bore 35 formed in stem 22. A'baflie cap 36 at the end of stem 22 is used to distribute the soapstone in a cloud'within the tube by causing the ejected soapstone to pass out through a number of small holes 37 in the perimeter of the cap bythe use of a compression shell 41 through which water is circulated.

Having thus described my invention I claim:

1. A tubing machine which comprises means for advancing plastic material, an outer die member, a spider, a stem carried by the spider, a core member supported by the stem and forming with the outer die member, an annular extruding die, a shell positioned on the stem intermediate the spider and core and adapted to compress the material just prior to its extrusion through the die and means to cool the shell.

2. A tubing machine which comprises means for advancing plastic material, an outer die member, a spider, a stem carried by the spider, a core member supported by the stem and forming with the outer die member an annular extruding die, a shell positioned on the stem intermediate the spidder and core and adapted to compressthe material just prior to its extrusion through the die and means to circulate a cooling fluid through the shell.

3. A tubing machine which comprises 0 means for advancing plastic material, an outer die member, a spider, a stem carried by the spider, a core member supported by the stem and forming with the outer die member an annular extruding die, a shell positioned on the stem intermediate the spider and core member and adapted to compress the material just prior to its extrusion through the die, and ducts formed in the spokes of the spider and communicating with 39 the interior of the shell for passing a cooling fluid through the shell.

CHARLES EDGAR MAYNARD. 

